Energy Flow Interrupted When Motor Stops Patents (Class 318/374)
  • Patent number: 9887663
    Abstract: A vehicle includes an electric motor to move the vehicle. A motor driver is configured to convert direct-current power supplied from a voltage converter to an alternating-current power and to convert the alternating-current power supplied from the electric motor to direct-current power. Circuitry is configured to drive the electric motor with a first current value to generate a drive force to consume excess electric power. The first current value is different from a minimum current value to generate the same drive force. The circuitry is configured to drive the electric motor with a second current value smaller than the first current value to decrease the electric power consumption of the electric motor when a temperature of the electric motor exceeds a first threshold temperature or a temperature of the motor driver exceeds a second threshold temperature.
    Type: Grant
    Filed: March 2, 2017
    Date of Patent: February 6, 2018
    Assignee: HONDA MOTOR CO., LTD.
    Inventors: Ken Kitaori, Masanari Fukuchi, Yoshihiro Ito, Satoshi Matsui
  • Patent number: 9024551
    Abstract: An integrated power converter includes first and second auxiliary switch modules, and one or more braking switch modules. The first auxiliary switch module is mounted at a first location of a laminated bus bar, and connects a first auxiliary lead with a first power layer and a second power layer of the bus bar. The second auxiliary switch module is mounted at a second location of the bus bar, and connects a second auxiliary lead with the first and second power layers. The braking switch modules are mounted at additional locations of the bus bar, adjacent to the first and second locations. Each braking switch module connects a braking lead with one of the power layers of the bus bar, and with a dual diode module or with the other power layer of the bus bar.
    Type: Grant
    Filed: December 31, 2012
    Date of Patent: May 5, 2015
    Assignee: General Electric Company
    Inventors: Alvaro Jorge Mari Curbelo, Henry Todd Young, Jason Daniel Kuttenkuler
  • Publication number: 20150091480
    Abstract: The invention is directed to a method for braking an electric drive motor having a stator and a rotor. The stator has field coils which have electrical phase connections for three motor phases. To generate an electromagnetic rotating field driving the rotor, the phase connections are connected to a supply voltage via switches actuated by a control unit which closes the switches depending on the rotary position of the rotor. To brake a rotating rotor, a braking current is generated by short-circuiting the phase connections. A phase short circuit is switched in between each two phase connections of the field coils with a preset temporal sequence to brake the rotor. The phase connections short-circuited are each selected corresponding to the rotary position of the rotor so that that field coil is short circuited in which the voltage induced by the magnetic field of the rotating rotor passes through its maximum.
    Type: Application
    Filed: September 23, 2014
    Publication date: April 2, 2015
    Inventors: Claudius Kischka, Simon Trinkle, Andreas Neubauer, Gernot Liebhard, Rene Wichert
  • Patent number: 8823298
    Abstract: A method of operating a laundry treating appliance to control a rotational speed of a drum to move the laundry within the drum according to a predetermined category of movement.
    Type: Grant
    Filed: March 14, 2012
    Date of Patent: September 2, 2014
    Assignee: Whirlpool Corporation
    Inventors: Biao He, Qiang Mei, Fabio E. Rosa
  • Patent number: 8742703
    Abstract: The invention relates to a blower apparatus (1) having a blower wheel (4) for generating a blower air flow (50). The blower wheel (4) is arranged in a housing (2), wherein the blower wheel is driven by an electric drive motor (8). A blower tube (6) via which the generated blower air flow (50) is guided connects at an outlet (5). A control unit (17) is provided for controlling the rotational speed of the electric drive motor. For a quick reduction of the blower air flow (50), it is provided that the control unit (17) supports the deceleration of the drive motor (8) through a braking current (I).
    Type: Grant
    Filed: December 15, 2011
    Date of Patent: June 3, 2014
    Assignee: Andreas Stihl AG & Co. KG
    Inventors: Andreas Binder, Arne Untermann, René Wichert
  • Patent number: 8736202
    Abstract: In a drive control circuit of a linear vibration motor, the drive signal generating unit generates a drive signal whose phase is opposite to that of the drive signal generated during the motor running, after the running of the linear vibration motor has terminated; this drive signal of opposite phase includes a high impedance period during which the driver unit is controlled to a high impedance state. An induced voltage detector detects an induced voltage occurring in the coil. A comparator has a function as a hysteresis comparator in which the output level does not vary in a predetermined dead band, and the comparator outputs a high-level signal or a low-level signal during the high impedance period. When an in-phase signal is consecutively outputted from the comparator during the consecutive high-impedance periods, the drive signal generating unit determines that the linear vibration motor has come to a stop.
    Type: Grant
    Filed: May 13, 2011
    Date of Patent: May 27, 2014
    Assignee: Semiconductor Components Industries, LLC
    Inventor: Tsutomu Murata
  • Patent number: 8710774
    Abstract: A drive control device for an electric train comprises a switch for connecting or opening direct-current power, a power converter into which the direct-current power is input via the switch between two terminals on an input side and which converts the direct-current power into alternating-current power through a switching action and drives an alternating current rotating machine connected on an output side, and a voltage detector for detecting the voltage between the two terminals. In addition, a power controller is provided that controls the power converter such that when the detected voltage of the voltage detector exceeds a predetermined open-circuit voltage, the switch is opened and the regenerative brake force is reduced by the alternating current rotating machine under a predetermined reduction pattern having a ramp reduction time longer than 0.
    Type: Grant
    Filed: December 18, 2009
    Date of Patent: April 29, 2014
    Assignee: Mitsubishi Electric Corporation
    Inventor: Kenichi Kusano
  • Patent number: 8614555
    Abstract: An actuator control system includes a controller and a buck-boost circuit. The controller is configured to direct power from a power source to an actuator. The actuator is coupled to a control device to apply a force related to operation of a vehicle. The buck-boost circuit is configured to direct excess power generated by the actuator to an energy storage device when an actuator power level satisfies an anticipated power level.
    Type: Grant
    Filed: March 23, 2012
    Date of Patent: December 24, 2013
    Assignee: The Boeing Company
    Inventors: James J. Sheahan, Jr., Thomas W. Omohundro, James L. Peck, Jr.
  • Patent number: 8587231
    Abstract: A power tool includes a housing, a brushless DC motor housed inside the housing, a power supply, a control unit, and an input unit such as a trigger switch actuated by a user. The control unit controls the commutation of the motor through a series of power switches coupled to the power supply. The control unit initiates electronic braking of the motor after occurrence of a condition in the input unit, such as trigger release or reduced speed, indicative of the power tool shut-down. A mechanism is provided to power the control unit for a predetermined amount of time after the detection of the condition from the input unit in order to complete the electronic braking of the motor.
    Type: Grant
    Filed: September 28, 2011
    Date of Patent: November 19, 2013
    Assignee: Black & Decker Inc.
    Inventor: Pradeep M. Pant
  • Patent number: 8456113
    Abstract: An electric switch for an electric tool with an electric motor. The switch has first electrical terminals for electrical connection to a voltage supply and second electrical terminals for electrical connection to the electric motor. The switch has an actuating mechanism which can be adjusted between an initial position and a final position, wherein the electric motor is switched off when the actuating mechanism is located in the initial position and is switched on when the actuating mechanism is not located in the initial position. The switch also has a braking circuit for braking the electric motor, the braking circuit operating when the actuating mechanism is reset to the initial position. The switch also has a reversal circuit for switching over the direction of rotation of the electric motor. The braking circuit is arranged between the second electrical terminals and the reversal circuit.
    Type: Grant
    Filed: August 30, 2011
    Date of Patent: June 4, 2013
    Assignee: Marquardt GmbH
    Inventors: Christof Lexer, Jens Müller, Andreas Seidel, Norbert Papok, Michael Tröndle
  • Patent number: 8421384
    Abstract: A direct current motor controlling apparatus may include a direct current motor driving unit to apply a driving voltage to a direct current motor and detect a predetermined signal from the direct current motor, and a servo-micom to control the status of the direct current motor using the signal detected by the direct current motor driving unit. Accordingly, the rotational status of the direct current motor is checked to control the direct current motor.
    Type: Grant
    Filed: September 17, 2009
    Date of Patent: April 16, 2013
    Assignee: SAMSUNG Electronics Co., Ltd.
    Inventor: Ho-chul Lee
  • Patent number: 8283879
    Abstract: A braking controller of a three-phase permanent magnetic brushless DC motor for directly driving a screw pump includes a detection circuit for detecting power supply states of the three-phase permanent magnetic brushless DC motor and a braking circuit for controlling the braking startup according to the power supply states of the three-phase permanent magnetic brushless DC motor. When the motor is supplied with power, the braking circuit is cut off. When the motor is not supplied with power and the screw pump drives the motor to reverse, the braking circuit starts up.
    Type: Grant
    Filed: August 4, 2006
    Date of Patent: October 9, 2012
    Assignee: Millennium Oilflow systems & Technology Inc.
    Inventors: Jun Liu, Yongjian Tang, Hengli Cong
  • Patent number: 8018182
    Abstract: The invention relates to a method for detecting an overload in an electric hand tool (10) comprising an electric motor (12), in particular a battery-driven electric hand tool (10). According to the invention, an operating current (iB) of the electric motor (12) is determined, the difference (ID) between the value of the operating current (IB) and at least one stored current value (IG) is determined and a thermal overload of the electric hand tool (10) is deduced from said difference (ID). The invention also relates to a corresponding monitoring device (22).
    Type: Grant
    Filed: July 17, 2006
    Date of Patent: September 13, 2011
    Assignee: Robert Bosch GmbH
    Inventors: Heiko Roehm, Wolfgang Hirschburger
  • Patent number: 7423393
    Abstract: A car control apparatus including a wheel sensor, wheel torque calculating means for calculating wheel torque from the wheel speed, drive force detecting means for detecting drive force generated by an electric motor, car body drive force calculating means for calculating car body drive force from the above drive force and wheel torque, car body drive force fluctuating component extracting means for extracting multiple frequency band fluctuating components of the car body drive force, and drive or braking force control unit for controlling the running state of a car.
    Type: Grant
    Filed: May 6, 2003
    Date of Patent: September 9, 2008
    Assignee: Kabushiki Kaisha Bridgestone
    Inventors: Yasumichi Wakao, Keizo Akutagawa
  • Publication number: 20080048597
    Abstract: A motor driving device includes a brake mode control section for starting, when a brake instruction for a motor, braking of the motor in a reverse brake mode and then switching the reverse brake mode to a short brake mode; a cycle start detection section for receiving a rotation signal and detecting a start of a cycle of the rotation signal for each cycle; and a counter for performing, when the start of the cycle of the rotation signal is detected by the cycle start detection section, a count operation from an initial value. In the motor driving device, the brake mode control section detects that a value of the counter exceeds a threshold and performs switching from the reverse brake mode to the short brake mode with a delay from the detection.
    Type: Application
    Filed: July 11, 2007
    Publication date: February 28, 2008
    Inventor: Shuji Tamaoka
  • Patent number: 7291997
    Abstract: A motor has built therein a brake for stopping the rotation of the motor and a brake controlling circuit for controlling the brake. The motor is further provided with a bypass circuit for supplying an electric power directly to the brake and a terminal for connecting a power source to the bypass circuit. When the brake controlling circuit develops a fault, the brake is directly released by an external power source.
    Type: Grant
    Filed: November 9, 2004
    Date of Patent: November 6, 2007
    Assignee: Nissan Motor Co., Ltd.
    Inventor: Takamasa Nakamura
  • Patent number: 7176645
    Abstract: A control apparatus for an electric railcar that provides control so that when rotational speed of a motor decreases below a required value, torque of the motor will decrease at a required rate of change, a current limiter for limiting a torque current command “(A)Iqp” output from a current command arithmetic unit is provided to ensure that when the rotational speed of the motor decreases below the required value, the torque current command will be limited to a command value “(B)Iqp” smaller than that command value, and to ensure that a carrier frequency at which PWM signals are created when switching elements of the electric power converter are controlled by carrier generator is controlled to become lower than a carrier frequency existing when the rotational speed of the motor decreases below the required value.
    Type: Grant
    Filed: April 18, 2005
    Date of Patent: February 13, 2007
    Assignee: Hitachi, Ltd.
    Inventors: Motomi Shimada, Akira Horie
  • Patent number: 7122982
    Abstract: A rotation information detection device detects rotation information of a DC motor based on a surge component waveform superimposed on a voltage waveform between the terminals of the DC motor or a current waveform of the DC motor, a circuit is provided which supplies a current of a current value Ipwm 45% during motor forward rotation or Ipwm 55% during reverse motor rotation to the motor over the period from when the motor starts braking operation to when it stops.
    Type: Grant
    Filed: May 26, 2005
    Date of Patent: October 17, 2006
    Assignee: Denso Corporation
    Inventors: Takanari Sasaya, Michiru Takahashi
  • Patent number: 6741051
    Abstract: A trigger controller for an electric power tool including a motor and a pull-trigger movable along a path having a foremost home position comprises a mechanical switch and a solid-state switch connected in series to the motor, wherein the mechanical switch includes a first moving contact, and the controller includes a second moving contact wherein the first and second moving contacts are movable to operate the mechanical and solid-state switches respectively at different predetermined travelling positions of the pull-trigger from the home position such that the two switches are caused to be initially closed at different times.
    Type: Grant
    Filed: November 29, 2002
    Date of Patent: May 25, 2004
    Assignee: Defond Manufacturing Limited
    Inventor: Raymond Wai Hang Chu
  • Patent number: 6291951
    Abstract: A holding brake control circuit is provided for use in conjunction with a servo-motor having an electrically operated holding brake. The holding brake has a pair of electric brake terminals and the brake is retained in a released condition as long as at least a preset brake voltage is maintained to the brake terminals. The holding brake control circuit includes a pair of output terminals connected to the electric brake terminals as well as a pair of power input terminals electrically connected to an electric power source. The electric power source, furthermore, has a higher voltage than the preset brake voltage. At least one capacitor is electrically connected in parallel with the input terminals so that the capacitor charges when power is applied to the input terminals. A voltage regulator has power inputs connected in parallel with the capacitor and a regulated voltage output connected in parallel with the output terminals for the control circuit.
    Type: Grant
    Filed: March 21, 2000
    Date of Patent: September 18, 2001
    Assignee: Valiant Machine & Tool Inc.
    Inventor: Dominique Baulier
  • Patent number: 6254352
    Abstract: A compressor control system including a controller for controlling the operation of a compressor, a power source unit for supplying power to the compressor, and a power converting device for subjecting the power from the power source unit to conversion processing and then supplying the power thus converted to the controller, the controller being reset on the basis of input of a reset signal to stop said compressor, is further provided with a power monitoring device for monitoring a power state (e.g., power failure or not) of the power source unit, and outputting the reset signal to the controller when the power supply of the power source unit is intercepted.
    Type: Grant
    Filed: December 30, 1998
    Date of Patent: July 3, 2001
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Atsusi Niizato, Kazuyoshi Suwa, Eiji Oohashi
  • Patent number: 6046559
    Abstract: A motor control method stops rotation of a motor which rotates in a forward direction by applying a brake signal for rotating the motor in a reverse direction. The motor control method detects a power supply voltage, and corrects a brake signal applying time for which the brake signal is applied to the motor depending on the detected power supply voltage.
    Type: Grant
    Filed: November 26, 1997
    Date of Patent: April 4, 2000
    Assignee: Fujitsu Limited
    Inventor: Masaaki Iwasaki
  • Patent number: 5717302
    Abstract: The invention relates to a motor stopped verification apparatus for verifying if a motor has stopped rotating, and in particular to rotation sensor technology for sampling rotation signals from a motor. With a first aspect of the invention, a high frequency current signal is supplied to the winding of a tachometer generator incorporated in a motor. This high frequency signal is modulated by an output signal from the tachometer generator, and the modulated signal made a motor rotation detection output from a rotation sensor. With a second aspect of the invention, a transducer coil is utilized as a part of an oscillator, and the motor rotation is converted to a change in the oscillation frequency of the oscillator and then sampled. With a third aspect of the invention, the motor rotation is converted by means of a resonance circuit incorporating the transducer coil, into a change in terminal voltage of the resonance circuit and then sampled.
    Type: Grant
    Filed: May 29, 1996
    Date of Patent: February 10, 1998
    Assignee: The Nippon Signal Co., Ltd.
    Inventors: Masayoshi Sakai, Toshihito Shirai, Hiroji Anzai, Koichi Futsuhara
  • Patent number: 5250883
    Abstract: There is provided a drive control apparatus for a motor having a drive device for controlling current supplied to an armature coil, a control device for controlling the rotation speed of a rotor, and a mode switch device for comparing a rotation speed signal and a predetermined reference voltage and generating a normal rotation mode signal or a reverse rotation mode signal. Furthermore, the drive control device has the drive device, the control device and a signal delay device. The signal delay device delays the supply of a stop signal from the control device by a predetermined time, and a reverse current is supplied to the armature coil during the delay time.
    Type: Grant
    Filed: February 18, 1992
    Date of Patent: October 5, 1993
    Assignee: Nippon Densan Corporation
    Inventor: Tadashi Okada
  • Patent number: 5010283
    Abstract: A motor control circuit provides reduced stopping time. The circuit utilizes n rotational signals whose relative phase differences are proportional to the rotational speed of the motor. Inverted logic signals are formed of these n signals. Circuitry for discriminating the direction of the motor and for determining from the n signals n-1 and/or n inverted signals, the initial change of any of the signals following a reversal of the motor. Upon determining the initial change, a signal is supplied to the motor drive circuit to cause the motor to de-energized. A specific circuit for holding the motor in a stopped condition is disclosed.
    Type: Grant
    Filed: January 12, 1990
    Date of Patent: April 23, 1991
    Assignee: Sankyo Seiki Mfg. Co., Ltd.
    Inventors: Kimio Kitajima, Hiroyuki Kiuchi
  • Patent number: 5006045
    Abstract: Here is disclosed an air conditioner comprising a scroll type compressor and a brushless DC motor having a rotor provided with a permanent magnet and a stator provided with a sensor adapted to detect a relative position of said rotor and said stator. Here is additionally disclosed an air conditioner in which the rotor of the brushless DC motor comprises a permanent magnet basically made of rare earth elements inclusive of yttrium, transition metal and boron and a driving circuit for the motor includes a braking circuit adapted to excite coils of the motor to thereby reduce reverse rotation of the rotor.
    Type: Grant
    Filed: December 16, 1988
    Date of Patent: April 9, 1991
    Assignees: Seiko Epson Corporation, Diesel Kiki Co., Ltd.
    Inventors: Tatsuya Shimoda, Takeshi Seto, Kenichi Endo, Yamaha Yoshikazu, Nobukazu Takagi
  • Patent number: 4926101
    Abstract: A DC motor is supplied, from a motor driver, with a brake voltage constituted by a forward drive voltage, a reverse drive voltage, and a stop voltage of a zero potential level. An operational current of the motor driver is supplied to a low-pass filter whose output is supplied to first and second sample and hold (S/H) circuits. The first S/H circuit performs its sampling operation after a minute period of time in which the brake voltage goes through a polarity inversion from the reverse drive voltage to the forward drive voltage. The second S/H circuit performs its sampling operation after a minute period of time in which the voltage applied is changed from the forward drive voltage to the reverse drive voltage. The outputs or sampled values of both S/H circuits are compared with each other by a comparator. When the sampled values equal each other, i.e., when the number of rotations of the motor becomes zero, the comparator outputs a coincidence pulse. This pulse is supplied to a stop detector.
    Type: Grant
    Filed: July 20, 1989
    Date of Patent: May 15, 1990
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Akihiko Enomoto, Takashi Koga, Minoru Yoneda, Hiroshi Kobata
  • Patent number: 4833378
    Abstract: A motor control method and apparatus in which when a motor rotating at prescribed RPM is to be stopped, a reverse maximum voltage is applied to the motor to rotate it in a reverse direction. Upon reversal of the direction of rotation of the motor, the reverse maximum voltage is cut off to stop the rotation of the motor in a shortest period of time.
    Type: Grant
    Filed: January 6, 1988
    Date of Patent: May 23, 1989
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Ryosuke Furue, Toshitaka Agano
  • Patent number: 4749923
    Abstract: A motor control device provided on an electric sewing machine comprising a brushless permanent-magnet motor and in combination with a magnetic pole sensor, rotational-speed and rotational-speed polarity detector for sewing machine, detectors for needle-position and needle positioning signal, and the control systems of speed and needle stagnation thereof; with the specific ways of controlling the needle stagnant position and the strength of the reverse current for braking the motor, simple structure, less power wastage and no wearable friction clutch and brake device are needed, a quick sewing machine starting, quick stabilizing of speed control and precise stagnation of the sewing needle at a preset position can be achieved.
    Type: Grant
    Filed: April 14, 1987
    Date of Patent: June 7, 1988
    Assignee: Yong Huei Hsing Electric Industries Corp.
    Inventor: Yu S. Chieng
  • Patent number: 4742282
    Abstract: A brake pulse forming circuit determines the rotational direction of a capstan motor in each edge of signals FG1 and FG2, utilizing D type flip-flops (21, 22, 23 and 24) and an NOR gate (25). A brake pulse f having a longer pulse width supplied from an intermittent driving circuit (10) to brake the capstan motor in a reverse direction is terminated by an AND gate (27), simultaneously with reverse detection of the capstan motor, and is applied to a capstan motor driving circuit as a corrected brake pulse j having a proper pulse width. In addition, a motor drive signal g supplied from the intermittent driving circuit (10) is terminated by an OR gate (26), simultaneously with reverse detection of the capstan motor. However, an EX-OR gate (28) prevents the motor driving signal g from being terminated by erroneous determination of the rotational direction at the time of starting the capstan motor.
    Type: Grant
    Filed: May 20, 1987
    Date of Patent: May 3, 1988
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Ayumu Okutani, Yukinori Konushi
  • Patent number: 4692676
    Abstract: The present invention provides a machine driving apparatus which is composed of a brushless motor for switching the energization phase of the stator winding in accordance with the position of a rotor with a permanent magnet being provided in a rotor as a machine driving motor, compares a speed instructing signal to be generated from a speed instructing unit 32 in accordance with the displacement amount of a machine pedal 31 with a speed detecting signal detected by a speed detector 44 to control the rotational speed of a motor 42, also damps in reverse operation the motor 42 with a stop instructing signal to be generated by a position instructing unit 33 in accordance with the operation of the machine pedal 31 and a needle position detecting signal detected by a needle position detector 46 to stop the machine needle in a given position.
    Type: Grant
    Filed: November 4, 1985
    Date of Patent: September 8, 1987
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Takashi Dohi, Nobuho Shibata, Kenichi Ohara
  • Patent number: 4629949
    Abstract: An apparatus for driving a turntable of a disc player system including a first drive voltage source for supplying a first driving voltage driving a spindle motor in a normal direction, a second drive voltage source for generating a second drive voltage for driving the spindle motor in a reverse direction, a voltage supply control circuit means for selectively supplying one of first and second drive voltages in accordance with a play command signal and a stop command signal, and a detection means for detecting the rotation of a rotor of the spindle motor in the reverse direction. When the stop command signal is supplied, the second drive voltage is supplied to the spindle motor for applying a driving torque of reverse direction to the rotor of the spindle motor and the supply of the second drive voltage is stopped immediately when the reverse direction rotation of the rotor is detected by the detection means. Thus, a very quick and accurate control of the stoppage of the spindle motor is realized.
    Type: Grant
    Filed: October 30, 1984
    Date of Patent: December 16, 1986
    Assignee: Pioneer Electronic Corporation
    Inventor: Hitoshi Senso
  • Patent number: 4139808
    Abstract: A sewing machine driven by a motor which is adapted to be energized by an alternate current power supply and is phase controlled by means of thyristors. In a normal operating mode the conduction phase of the thyristors is made variable as a function of the extent of the depression of a foot controlled pedal, whereas in a low constant speed mode the thyristors are made conductive at a predetermined phase. The motor is coupled to a main shaft which is provided with a magnet located at a predetermined position, while a bracket arm is provided with a reed switch located at a predetermined position, such that if and when the foot controlled pedal is released, the reed switch is actuated to trigger the thyristors for reverse braking of the motor as a function of the counter electromotive force of the motor. Preferably, a timer is provided for interrupting the power supply after the lapse of a predetermined time period after the foot controlled pedal is released.
    Type: Grant
    Filed: September 9, 1977
    Date of Patent: February 13, 1979
    Assignee: Maruzen Sewing Machine Co., Ltd.
    Inventor: Nobuyoshi Matsumura
  • Patent number: 4087078
    Abstract: A moving apparatus for a load lifts the load by the torque of a motor, and balances and holds the same with the aid of a mechanical brake when the apparatus stops. A timing device is incorporated in brake control so that when the apparatus stops in response to a signal indicating that a zero speed is designated, the mechanical brake is operated with a time lag after the receipt of the signal and, as soon as the brake is applied, the power supply to the motor is cut off. This arrangement remarkably reduces the impact of stopping upon the mechanical brake and drive, lessens the wear of the brake, permits reduction in size of the components and extends the service life of the components, thus providing an apparatus which saves power in comparison with conventional equipment.
    Type: Grant
    Filed: April 14, 1976
    Date of Patent: May 2, 1978
    Assignee: Hitachi, Ltd.
    Inventors: Masami Joraku, Koji Yamauchi, Shigeyoshi Kawano, Masahiro Ueno
  • Patent number: 3969663
    Abstract: A control system for precisely locating a tape upon deceleration thereof from a transport velocity to rest. A signal is generated which represents the distance traversed by the tape subsequent to an identified event. The signal is compared with a reference signal representing a desired distance-versus-time characteristic, and the error signal thus given rise to is used to either "plug" or dynamic brake the motor to control the stopping distance. Final position control logic produces and additional enabling signal should the tape overrun its desired position, and causes the motor to reverse to reposition the tape. In a preferred embodiment, a current limit circuit monitors current through the drive motor, and intermittently disables a portion of the drive circuit in response to a sensed overcurrent condition.
    Type: Grant
    Filed: October 17, 1974
    Date of Patent: July 13, 1976
    Assignee: Storage Technology Corporation
    Inventors: William C. Arthur, William W. Steger